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15f30f5131
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Nandor Han 15f30f5131 dmaengine: imx-sdma - reduce transfer latency for DMA cyclic clients 
Having the SDMA driver use a tasklet for running the clients
callback introduce some issues:
  - probability to have desynchronized data because of the
    race condition created since the DMA transaction status
    is retrieved only when the callback is executed, leaving
    plenty of time for transaction status to get altered.
  - inter-transfer latency which can leave channels idle.

Move the callback execution, for cyclic channels, to SDMA
interrupt (as advised in `Documentation/dmaengine/provider.txt`)
to (a)reduce the inter-transfer latency and (b) eliminate the
race condition possibility where DMA transaction status might
be changed by the time is read.

The responsibility of the SDMA interrupt latency
is moved to the SDMA clients which case by case should defer
the work to bottom-halves when needed.

Tested-by: Peter Senna Tschudin <peter.senna@collabora.com>
Acked-by: Peter Senna Tschudin <peter.senna@collabora.com>
Reviewed-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 16:27:28 +02:00
..
accessibility
acpi libnvdimm, nd_blk: mask off reserved status bits 2016-08-08 09:26:13 -07:00
amba
android
ata New LED class driver: 2016-07-27 14:03:52 -07:00
atm drivers: atm: nicstar: Use the correct function to free some resources 2016-07-19 11:30:26 -07:00
auxdisplay
base More power management updates for v4.8-rc1 2016-08-05 23:26:16 -04:00
bcma wireless-drivers-next patches for 4.8 2016-07-25 11:09:19 -07:00
block virtio/vhost: fixes and cleanups for 4.8 2016-08-11 14:10:23 -07:00
bluetooth Bluetooth: btmrvl: reset is_suspending flag in failure path 2016-07-18 10:13:02 +02:00
bus ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
cdrom
char RTC for 4.8 2016-08-05 09:48:22 -04:00
clk treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
clocksource Merge branch 'linus' into timers/urgent, to pick up fixes 2016-08-10 14:36:23 +02:00
connector
cpufreq Merge branches 'pm-sleep' and 'pm-cpufreq' 2016-08-12 22:53:58 +02:00
cpuidle powerpc updates for 4.8 # 1 2016-07-30 21:01:36 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-08-01 14:28:42 -04:00
dax
dca
devfreq
dio
dma dmaengine: imx-sdma - reduce transfer latency for DMA cyclic clients 2016-08-31 16:27:28 +02:00
dma-buf dma-buf: Release module reference on creation failure 2016-07-18 14:10:49 +02:00
edac * Altera Arria10 ethernet FIFO buffer support (Thor Thayer) 2016-07-27 13:40:47 -07:00
eisa
extcon
firewire
firmware efi/capsule: Allocate whole capsule into virtual memory 2016-08-11 13:55:36 +02:00
fmc
fpga drivers/fpga/Kconfig: fix build failure 2016-08-04 08:50:07 -04:00
gpio This is the bulk of GPIO changes for the v4.8 kernel cycle. 2016-07-26 19:16:01 -07:00
gpu drm/cirrus: Fix NULL pointer dereference when registering the fbdev 2016-08-09 13:01:47 +10:00
hid Merge branch 'for-4.8/hid-led' into for-linus 2016-07-28 10:49:23 +02:00
hsi
hv
hwmon hwmon updates for v4.8 (take 2) 2016-08-01 16:49:13 -04:00
hwspinlock
hwtracing Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
i2c powerpc updates for 4.8 # 1 2016-07-30 21:01:36 -07:00
ide Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide 2016-07-29 13:29:06 -07:00
idle Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-30 12:56:26 -07:00
iio
infiniband Second round of merge items for 4.8 2016-08-04 20:26:31 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-08-05 23:24:15 -04:00
iommu dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
ipack
irqchip tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
isdn
leds powerpc updates for 4.8 # 1 2016-07-30 21:01:36 -07:00
lguest
lightnvm block: get rid of bio_rw and READA 2016-07-20 17:37:01 -06:00
macintosh powerpc updates for 4.8 # 1 2016-07-30 21:01:36 -07:00
mailbox mailbox: Fix format and type mismatches in Broadcom PDC driver 2016-07-28 21:27:31 +05:30
mcb
md block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
media media updates for v4.8-rc1 2016-08-04 09:59:37 -04:00
memory MTD updates for v4.8: 2016-08-02 17:05:11 -04:00
memstick memstick: don't allocate unused major for ms_block 2016-08-02 17:31:41 -04:00
message
mfd ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
misc powerpc fixes for 4.8 #3 2016-08-12 12:09:44 -07:00
mmc MMC core: 2016-07-31 21:36:58 -04:00
mtd This pull request contains mostly cleanups and minor 2016-08-04 19:51:49 -04:00
net virtio/vhost: new features for 4.8 2016-08-06 09:20:13 -04:00
nfc NFC 4.8 pull request 2016-07-20 23:39:36 -07:00
ntb NTB: ntb_hw_intel: use local variable pdev 2016-08-05 10:34:13 -04:00
nubus
nvdimm nvdimm, btt: add a size attribute for BTTs 2016-08-08 09:26:14 -07:00
nvme nvme: Suspend all queues before deletion 2016-08-11 09:35:57 -06:00
nvmem
of ramoops: use DT reserved-memory bindings 2016-08-05 11:21:36 -07:00
oprofile
parisc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
parport
pci genirq/msi: Make sure PCI MSIs are activated early 2016-08-09 09:19:32 +02:00
pcmcia
perf drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property 2016-08-09 17:57:39 +01:00
phy MMC core: 2016-07-31 21:36:58 -04:00
pinctrl This is the bulk of pin control changes for the v4.8 kernel cycle. 2016-07-28 17:06:51 -07:00
platform dell-wmi: Ignore WMI event 0xe00e 2016-08-08 11:00:21 -07:00
pnp PNP: pnpbios: add header file to fix build errors 2016-07-27 18:52:54 +02:00
power ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
powercap
pps pps: do not crash when failed to register 2016-07-23 10:25:54 +09:00
ps3
ptp
pwm pwm: Changes for v4.8-rc1 2016-08-06 00:01:33 -04:00
rapidio rapidio: dereferencing an error pointer 2016-08-10 16:40:56 -07:00
ras
regulator pwm: Changes for v4.8-rc1 2016-08-06 00:01:33 -04:00
remoteproc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
reset
rpmsg
rtc RTC for 4.8 2016-08-05 09:48:22 -04:00
s390 virtio/s390: deprecate old transport 2016-08-09 13:42:41 +03:00
sbus
scsi ipr: Fix sync scsi scan 2016-08-09 10:17:42 -07:00
sfi
sh
sn
soc ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
spi ARM: DT updates for v4.8 2016-08-01 18:37:45 -04:00
spmi
ssb
staging Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-08-07 10:01:14 -04:00
target target: iblock_execute_sync_cache() should use bio_set_op_attrs() 2016-08-07 14:41:02 -06:00
tc
thermal Merge branches 'thermal-intel' and 'thermal-core' into next 2016-08-08 10:59:35 +08:00
thunderbolt
tty serial: 8250_lpss: enable DMA on Intel Quark UART 2016-08-31 16:13:30 +02:00
uio
usb More USB patches for 4.8-rc1 2016-08-05 23:07:43 -04:00
uwb
vfio vfio/pci: Fix NULL pointer oops in error interrupt setup handling 2016-08-08 16:16:23 -06:00
vhost vhost/vsock: fix vhost virtio_vsock_pkt use-after-free 2016-08-09 13:42:37 +03:00
video dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
virt
virtio virtio: fix error handling for debug builds 2016-08-09 13:42:35 +03:00
vlynq
vme
w1 w1:omap_hdq: fix regression 2016-08-02 19:35:40 -04:00
watchdog watchdog: gpio_wdt: Fix missing platform_set_drvdata() in gpio_wdt_probe() 2016-07-27 10:47:43 +02:00
xen dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
zorro
Kconfig
Makefile virtio/vhost: new features for 4.8 2016-08-06 09:20:13 -04:00